ref: 6184a4ef2eba1d49f0386e9ce94f4877d3d9edb2 dir: /sys/src/libc/68020/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4